Rotary switch cap seal



Oct. 11, 1966 M. MORSE 3,277,739

ROTARY SWITCH CAP SEAL Filed May 15, 1964 United States Patent 3,277,739ROTARY SWITCH CAI SEAL Milton Morse, 1 Horizon Road, Fort Lee, NJ. FiledMay 15, 1964, Ser. No. 367,680 1 Claim. (Cl. 74558.5)

This invention relates generally to the field of rotary hermetic seals,and more particularly to an improved form thereof especially adapted toeffect a seal about an operating button as the same projects outwardlyfrom an opening in a plate or other planar surface. Devices of thisgeneral type are known in the art, and the invention lies in specificconstructional details permitting the seal to be maintained as thedevice is moved with respect to the outer surface with which it makes aseal.

It is among the principal objects of the present invention to provide animproved seal of the class described which may be conveniently andeconomically molded as a single injection of elastomeric material suchas silicon rubber or the like.

Another object of the invention lies in the provision of an improvedsealing device including an inwardly flared sealing flange or lip whichresiliently and slidably contacts the surface with which the seal ismade, whereby the switch disposed therebeneath may be rotated to makeand break contact without disturbing the sealing action.

Yet another object of the invention lies in the provision of an improvedseal of the class described in which the cost of fabrication may be of areasonably low order, with consequent wide sale, distribution and use.

Yet a further object of the invention lies in the provision of animproved sealing device of the class described which may be convenientlyinstalled and removed without the use of special tools, and by thosepossessing only ordinary skill, and which will not be readilyaccidentally removed or disturbed to a condition in which the sealingaction will be lost.

A feature of the invention lies in the fact that the device, in additionto providing a sealing action, provides an improved grip for the fingersof the user in operating the switch disposed therebeneath.

Another feature of the invention lies in the attractive externalappearance of the same.

These objects and features, as well as other incidental ends andadvantages, will more fully appear in the progress of the followingdisclosure, and be pointed out in the appended claim.

In the drawing, to which reference will be made in the specification,similar reference characters have been employed to designatecorresponding parts throughout the several views.

FIGURE 1 is a plan view of an embodiment of the invention.

FIGURE 2 is a central longitudinal sectional view of the embodimentshowing the same in installed condition upon a conventional rotaryswitch.

FIGURE 3 is a bottom plan view of the embodiment.

FIGURE 4 is a side elevational view thereof.

In accordance with the invention, the device is illustrated in FIGURE 2in the drawing in operative connection with a rotary switch 11 of a typeincluding a rounded button 12 beneath which switch contacts (not shown)are disposed. The button 12 includes a shank portion 13 positionedwithin an opening 14 in a sheet metal plate 15 which may be a part of anelectrical or electronic chassis, being secured therein by a retainingnut 16 or other suitable means (not shown). As seen in FIGURE 2, thebutton 12 includes an upper generally planar surface 18, a slightlytapered side surface 19, and a lower edge surface 20. The upper surface18 meets the side surface 19 Patented Oct. 11, 1966 in an uppercurvilinear edge 21, the side surface meeting the lower surface 20 in asimilar curvilinear edge 22.

The device 10, as has been mentioned is formed integrally to include abody of flexible resilient material, such as silicon rubber, naturalrubber, or the like, and includes a generally planar upper wall 25adapted to overlie the upper surface 18, the same being bounded by anouter surface 26 and an inner surface 27 as well as a peripheral edge28. Interconnected at the edge 28 is a tapered side wall 29corresponding to the side surface 19, again including an outer surface30 having ribbed elongated projections 31 thereon to facilitate manualengagement, and a relatively smooth inner surface 32 adapted tofrictionally grip the surface 19. The side wall 29 includes a lower edge33, of arcuate configuration, to which are attached a first inwardlydirected flange 34 and a second outwardly directed flange 35. The flange34 lies substantially in a plane parallel to that of the upper wall 25,and overlies the lower surface 20 to a degree suflicient to retain thedevice 10 upon the button 12. The flange 35 is flared radially outwardlyin a direction away from the upper wall 25, and is best seen in FIGURE2. The same is formed to include a tapered cross section which convergesto a feathered edge 36 at the point of contact with the surface of theplate 15, whereby a gentle resilient pressure is constantly exerted uponsaid surface sufficient to maintain a hermetic seal thereat. Thissealing action may be assisted, if necessary, by the use of a smallamount of silicone grease at the area of contact, but is by no meansessential.

I wish it to be understood that I do not consider the invention limitedto the precise details of structure shown and set forth in thisspecification, for obvious modifications will occur to those skilled inthe art to which the invention pertains.

I claim:

A cap-type seal for use in conjunction with a rotating knob, comprising:a unitary molded body of flexible resilient material, said body having aprincipal axis, and including a substantially planar outer wall disposedperpendicularly to said axis, a continuous curvilinear side wallinterconnected at one peripheral edge thereof to said outer wall andforming a recess for reception of said knob, said side wall having asecond oppositely disposed peripheral edge, a first radially inwardlydirected flange connected to said side wall at said second peripheraledge, said inwardly directed flange having an inner diametersubstantially less than the greatest diameter of said recess when saidseal is in relatively unstressed condition, and a second outwardlydirected flange also connected to said side wall at said secondperipheral edge, said second outer flange being flared in a directionaway from said outer wall, and having a free edge portion thereof oftapered cross section, said second outer flange defining a featherededge lying in a plane perpendicular to said principal axis.

References Cited by the Examiner UNITED STATES PATENTS 2,440,170 4/ 1948Duefrene. 3,101,205 8/ 1963 Benham. 3,185,806 5/1965 Bowman et a1 2001683,218,427 11/ 1965 Mekel burg 200168 OTHER REFERENCES Westinghouse,November 1959; Product Engineering (design edition) vol. 30, #46, pp.12-13.

FRED C. MATTERN, 111., Primary Examiner.

C. F. GREEN, Assistant Examiner.

